Abstract: A dispenser safety attachment for liquid additives and particularly for periodically dispensing increments of liquid additive which are corrosive, carcinogenic or otherwise possess qualities which suggest that contact therewith be avoided. The device is characterized by the provision of a receptacle adapted to be secured to a tank or like receiver or conduit for materials to be treated and a container adapted to be mounted in the receptacle, the container including a valve mechanism, known per se, and subject to opening and closing by relative rotation of the container and a spout. The receptacle and container interact in such manner that increments of the liquid in the container may be dispensed by relatively rotating the container and receptacle which has been mounted on the tank by torsional forces applied to the container.